This message drives me crazy. There's still plenty of toner. I went to an online consultant and asked this:
How can I stop my D420 from telling me the toner is low (or gone) when there is still plenty of toner? Can I stop these warnings completely? I can tell when the toner is low enough to affect the print quality.
I received this answer:
There is a chip on the toner cartridge that provides information on page count and from that, the printer determines that the cartridge is empty. There is no way to reset it or fool it or stop the warnings - they are a built-in function of this printer.
Hard to believe that they want to sell cartridges so much that they build in a false, early warning. Eventually it stops printing entirely, demanding a new cartridge.
I replaced the cartridge giving the warning with a new one and printed a few copies. Then I replaced the new cartridge with the old one previously giving the warning. It continued giving an out-of-toner warning, but it also continued printing, showing that the previous warning was premature and false. I speculate that I can actually use up all the toner by moving the used cartridges out and back in this way. Inconvenient, but it works. This inconvenience, however, suggests that I should try a brand other than Canon when I'm ready for a new printer.
